While problematic behaviors can hamper children’s early positive development, the teacher–child relationship can play a crucial role in mitigating children’s externalizing problem behavior (EPB).This review aims to systematically examine and synthesize evidence on the effectiveness of interventions designed to enhance teacher–child interactions (TCIs) and assess their impact on reducing EPB among children in childcare settings. Systematic literature searches were performed on four electronic databases (EBSCO, ERIC, SCOPUS, and WOS). A complementary search of clinical trial registries (clinicaltrials.gov) was performed. The studies reported on interventions targeting the promotion of TCI to reduce children’s EPB in childcare settings. The children were aged 0–6 years, and their EPB was assessed using self-report questionnaires and/or observational coding instruments. The risk of bias was evaluated using the Joanna Briggs Institute’s Critical Appraisal Tool. The standardized mean differences were pooled using random effects, and a moderator analysis was conducted. The review included 26 studies, 12 of which were included in a meta-analysis, revealing a significant decrease in children’s EPB (SMD = −0.240; 95% CI = [−0.362, −0.117]; p = 0.001). Tier-2 interventions implemented within the Multi-Tiered Systems of Support (MTSS) framework were particularly effective (SMD = −0.508; 95% CI: [−0.755, −0.261]). Furthermore, interventions that integrated video components also showed significant effectiveness (SMD = −0.303; 95% CI: [−0.434, −0.172]). This review emphasizes the importance of enhancing TCIs to reduce children's EPB and recommends innovative training methods and long-term follow-up studies for improved effectiveness.